the more i took, the more i felt myself grow during my workouts, it's kind of weird to say, but it always seemed like i could actually feel myself growing after about 45min-an hour of pinning my slin pre-workout. i never exceeded 15 iu's at 220lbs. my buddy made his way up to 19iu's @255-260 and stayed there. i'll be going back on slin this fall and will be starting with 12 iu's and working my way back up to 15 just in case my insulin sensitivity has changed.
in case anyone is wondering why i mentioned weights in there, we based our doses off of what we thought a good portion of our carbs would be to dedicate pre, intra, and post workout from our daily carb allotment for the day. the more you weigh, the more cals you need, the more carbs you need, the more IU's you pin to take advantage of more carbs being allotted to "slin time". that's at least how we looked at it.